Absorbent articles, such as diapers for children and adults, have long been provided with fastener devices by means of which, e.g., a parent is able to fasten together respective corner parts of the front and rear diaper parts, such that the diaper will sit around the wearer's abdomen in a pants-like fashion. These fastener devices can subsequently be released to permit removal of the diaper after use. Examples of such fastener devices are adhesive coatings and mechanical locking devices. These latter devices may have the form of press studs, buttons and button holes, so-called touch and close fasteners (i.e. fasteners comprising hook and loop fastener elements). Both the adhesive and mechanical fasteners may be mounted on fastener tabs attached to the article, conveniently in the vicinity of the two corner portions of the rear part of the diaper.
Examples of diapers provided with such adhesive fastener tabs are described in Swedish Patent Specification 446 056. The diaper according to SE 446 056 is also provided with one or more plastic strips attached along the end edge of the diaper and extending from corner to corner on the front part of the diaper. When using the diaper, the plastic strip or strips functions/function as an attachment surface for fastening of the fastener tabs. The plastic strip is of a nature which will allow the fastener tabs to be released therefrom without detriment either to the adhesive coating on the tabs or to the plastic strip. This enables the fastener tabs to be refastened to the plastic strip, e.g. after a parent has inspected the diaper to ascertain whether or not the diaper needs to be changed and has not found this to be the case.
It is known to use mechanical fastener devices as diaper fastener means as an alternative to adhesive fastener means. European Patent Specification EP 0 235 014 B1 is an example of the patent literature relating to diapers provided with mechanical fastener tabs. The fastener system described in this specification is similar in many respects to the system illustrated in SE 446 056, but with the difference, of course, that the fastener means are mechanical, more specifically of the touch and close type.
It is also known to attach fastener devices directly to the inside or the outside of the diaper casing, i.e. in the total absence of fastener tabs.
The fastener systems of the kind described in SE 446 056 and EP 0 235 014 B1 also include fastener tabs which are elongated in the transverse direction of the diaper and which are substantially narrower than the distance between the end edge of the diaper at the diaper waist opening and respective diaper leg openings. These fastener tabs are normally less than 25 mm in width. On the other hand, EP 0 215 408 for instance describes fastener devices which are mounted directly on the diaper casing essentially in the longitudinal direction of the diaper and which extend fully from the diaper waist opening to respective diaper leg openings.
The diaper illustrated in EP 0 215 408-1 also has an elastic outer casing which can be stretched and allowed to contract around the wearer's body.
SE 9500386-9 (filing date Feb. 2nd, 1995) describes an absorbent pant diaper that includes an elastic pants-type sheet or layer which fits tightly against the wearer's body, whereas the outer casing sheet and the absorbent body are essentially unaffected by forces stemming from the pants-type layer.
Diapers will normally have elastic rear and front parts, sometimes limited to certain zones of said parts, for instance along the end-edges or in the corner portions of the front and/or rear parts of the diaper. The purpose of making the whole or parts of the front and rear parts of the diaper elastic is to enable the diaper to sit tightly around the waist of the wearer. This so-called waist elastic is intended to hold the diaper tightly against the wearer's body so that no urine will leak through the diaper waist opening, and also to keep the diaper in position on the wearer's body when the diaper has absorbed liquid to an extent which causes the diaper to sag.
One of the most usual methods of applying a diaper provided with the aforesaid types of fastener devices is to place the diaper carrier (e.g. a baby) on its back and to pass the rear part of the diaper beneath the baby's bottom and then past the part of the diaper between the legs and up over the baby's stomach. The front and rear diaper parts are then mutually secured by means of the fastener devices.
Absorbent articles that include elastic rear parts, primarily such articles that include relatively strong elastic, often exhibit relatively heavily contracted rear parts when no load acts on the diaper. This is because the rear part of the diaper, and primarily its rear corner portions, generally consist solely of relatively pliable casing material, such as nonwoven material and polyethylene film.
As a result of this heavy or pronounced contraction, a parent attempting to put a diaper on a baby with the baby lying on its back, ie in a so-called recumbent position, may find it difficult to grip the corners of the diaper, because the rear diaper part has contracted elastically to such an extent as to draw the corners inwardly beneath the baby's bottom or backside.
With regard to diapers provided with fastener tabs, it is feasible in theory that the corners could be gripped more readily if the corners were larger in size, since this would enable the fastener tabs to be used as "handgrips". However, in the packaged state of the diaper, fastener tabs are normally folded in over the diaper casing material and releasably fixed thereto. When the fastener means is an adhesive, fastener tabs may be fastened to a release layer or film on the casing material or to a region of the casing material that has been treated with a release agent. Fastener tabs provided with mechanical fastener elements are also normally folded in over the diaper casing material in a corresponding manner.
In order to avoid the adhesive coming into contact with the wearer's skin, the fastener tabs are not released until they are to be fastened to the front part of the diaper. If the fastener tabs are released prematurely, the risk of the fastener means coming into contact with the wearer's skin is extremely great in the case of diapers whose rear parts are heavily contracted by elastic devices, since, as before mentioned, the corners of such diapers will be located beneath the wearer's body when the wearer lies on his/her back. Consequently, it is not possible in practice to use the fastener tabs as a form of grip in order to obtain better purchase when the corner parts of the diaper lie beneath the wearer and cannot readily be reached.
When the fastener means has the form of mechanical fastener elements, for instance touch and close fasteners, instead of an adhesive, there is a corresponding desire to prevent the wearer's skin becoming marked by said fastener means, and consequently such fastener tabs are equally as unsuitable for use as gripping means as the adhesive fastener tabs under corresponding conditions.
The use of fastener tabs with diapers that include relatively large elastic regions in the front and/or rear parts of the diaper also leads to another drawback. A fastener tab is normally relatively non-elastic and has its largest extension in the waist region of the diaper. Consequently, the fastener tab occupies a not inconsiderable portion of the front diaper part when fixed thereto, thereby impairing the elasticity of said front part. Naturally, that portion of the fastener tab which in manufacture is permanently attached to the respective corner portions of the rear diaper part will also occupy a not inconsiderable portion of the rear diaper part, thereby preventing this portion being used to apply elastic forces to the diaper with the intention of keeping the diaper in place on the wearer. In other words, a smaller part of the waist region of the diaper can be used to generate diaper holding elastic forces when the diaper is provided with transversely extending fastener tabs that when such tabs are not included.
Those diapers with which fastener devices are mounted directly on the diaper casing, similar to the diaper according to EP 0 215 408 B1, have other drawbacks. Since such devices need to be relatively long in order to extend from the edge of the waist opening to respective leg openings, they are also longer than the normal finger breadth of a human hand. Consequently, such devices are difficult to apply to their corresponding fastener devices (which are equally as long) in the corners of the front diaper part with the same grip as that taken on the fastener device in order to stretch the elastic in those parts of the diaper extending around the waist region. The fingers used to secure the fastener devices are also liable to become positioned between those fastener devices that are to be mutually secured, which is undesirable of course.